I think all of the above snippets work, but it's not how I would have done it, so here it is:
#!/usr/bin/perl -w

use strict;

$/ = undef;
open (FILE, "< input.txt") or die $!;
my $file = <FILE>;
close FILE;
# only standard stuff so far..

# this will hold the key's value
my $value;

# remove comments..
$file =~ s/;.*$//g;

# check for the block we want
if ($file =~ m/\*DESCRIPTION.+?\*END/s)
{
    my $block = $&;
    # look for the keyword within the block
    if ($block =~ m/^$keyword\s*=\s*(.+)$/)
    {
        $value = $1;
    }
    else
    {
        $value = "Pattern not found, sorry";
    }
}
else
{
    $value = "Block not found.. Please check!";
}

print $value . "\n";

[download]
So, now you have enough examples.. Take your pick ;)

-octo-

In reply to Do this using regular expressions (my solution..) by flocto
in thread Search for a BLOCK of text and selectively replace by Rhodium

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